Heat Transfer and the Space Shuttle

This paper was written to explain the Thermal Protective Systems (TPS) of the space shuttle to a non-scientific audience.

This paper talks about the ways in which the shuttle is designed to overcome basic heat transfer problems during launch, orbit and re-entry. The main points in this paper are the active and passive systems in the TPS and the history of the shuttle design.

“10…9…8…Patiently the Space Shuttle waits on the launch pad…7…6… everything is in place…5…4… all functions are working properly…3… the conditions are comfortable on the coast of Florida, and the temperature is nice and warm…2…1… IGNITION! (Figure #1) The sudden burn of the rockets jolts the humongous craft to life. As streams of flame shoot out its lower portion, the craft begins to inch skyward. In no time its speed has increased, and it begins hurtling through the air towards its mission. While still inside Earth’s atmosphere, the airflow over the Shuttle begins to warm the craft’s surface, until it becomes “white hot.” Then, the craft breaks free of the atmosphere’s restraints, plunging into the freezing void of outer space. The Space Shuttle must be able to withstand these temperature extremes and still accomplish its mission objectives. After the mission, as the craft returns to Earth, it again encounters tremendously high temperatures as it re-enters Earth’s atmosphere. The Shuttle encounters a lot of atmospheric resistance and slows itself down through this phase, then finally glides to a comfortable rest at Edwards Air Force Base in sunny Southern California, where the astronauts and craft must prepare to begin the process all over again. These intense hot and cold extremes drive scientists and design engineers as they work to control the internal temperature of the space shuttle throughout the various phases of its journey. They do this by using many creative systems such as specially designed tiles and radiator systems, to both reflect and radiate heat that would otherwise be dangerous to the craft and crew.”